Ultimate Strength Evaluation And Engineering Application Of Stiffened Panel With Corrosion Damage

Ships in service for a long time in the corrosive environment,it is difficult to avoid corrosion damage.Corrosion will lead to plate thickness reduction,limit load capacity reduction.Pitting is a kind of inhomogeneous corrosion widely existed in hull structure,which will lead to the destruction of structural integrity and cause greater strength loss.As the basic stressed member in ship structure,the stiffened panel will be unstable or even fail if the load exceeds its ultimate strength,so it is of great significance to evaluate the ultimate strength of the stiffened panel with corrosion damage accurately.In this paper,the influence of corrosion parameters on the ultimate strength of corrosion-damaged stiffened panel structure is studied by using the nonlinear finite element method,and an assessment method of ultimate strength for engineering application is proposed.The research content mainly includes:(1)select the appropriate model range,initial defects,grid size,and establish an accurate finite element model;(2)study the influence of factors such as pit shape,corrosion position,plate slenderness ratio,stiffener slenderness ratio,DOP,corrosion depth,corrosion volume,number of stiffener,and stiffener corrosion on the ultimate strength of the stiffened panel;(3)study the recognition method of collapse mode of stiffened panel and the change trend of collapse mode;(4)according to the results of numerical calculation,appropriate evaluation parameters are selected to fit the accurate ultimate strength evaluation formula of the reinforced plate structure with corrosion damage;(5)the calculation method of corrosion volume is studied according to the corrosion data,and the software is compiled based on the evaluation method,which is convenient for engineering application.Based on the above research work,it can be seen that the corrosion volume is an important evaluation parameter for the ultimate strength reduction.The formula for the ultimate strength evaluation of the stiffened panel with corrosion damage based on the corrosion volume is more accurate.The evaluation method proposed in this study can quickly and accurately evaluate the ultimate strength of the stiffened panel with corrosion damage and has important practical application value.